okay so this is a tough one. the movie is an older one probably from the 70's or 80's. and i can only remember bits and pieces.1) there are girls i THINK they're aliens but they look completely normal and are very busty.2) they ( there are 2 or 3) really like sex3) one 'rapes" guy in a lake4) one wants to have sex with some guy, she goes under his deck and plays with his..you know.. while he is trying to work.. so she goes to the bed and plays with herself.... he doesn't like it so he comes and rapes her..

i know it isn't much to go off but it was actually a pretty interesting movie.

I am guessing that this is not a XXX film. That would be a whole new can of worms.

There are a number of films made in this little niche. The trick is finding which one fits your description. The two scenes to try to find are the lake and under the deck. If you can remember any more specific scenes, it could help pin down the film. The fact that all of the women are "very busty" does not fit with many of the films made before 1985 or so - especially if the movie was made outside the US.

"Spermula" (1976) is a possibility.

I do not remember any of Russ Meyer's films having aliens, but he jumps to mind as a possible director of this kind of film - and he usually made films that are memorable. This is his IMDb profile: